Illuminated speedometer



Jul 19, 1938.

H. C. STUERZL ILLUMINATED SPEEDOMETER Filed Aug. 26, 193'? Zinbentor attorneys Patented July 19, 1938 UNITED STATES poration of Delaware Application August 26, 1937, Serial No. 160,969

3 Claims.

This invention relates to the illumination of indicating instruments and in addition to other uses, it is intended particularly for the illuminaand not be confused by directly transmitted light.

Another and more specific object is concerned with an improvement in the means for the transmission of light from the source to a part'of a rotating pointer, the latter adapted to be assod. reflected to the observer. To make best use of the ated with illuminated characters on a glass plate.

Other objects and advantages will be understood from the following description.

I The invention is illustrated by the accompanying drawing in which:

Figure 1 is a transverse section through the improved instrument.

Figure 2 is a view in front elevation.

Figure 3 is a detail in perspective.-

Referring to the drawing a housing is formed by a boundary wall of metal I to which is secured a rear wall 9 and to the latter is attacheda cup H carrying instrument operating mecha nism for a combined odometer and speedometer. The cup is shown with a boss l3 for the passage of a driven shaft not shown. At the front of the housing is shown an opaque plate [5 having a large central opening". Overlying plate I5 is a Lucite face I9. An annular ring 2| is clamped over the housing flange 23, the extremity of plate l5 and the Lucite face l9. Within the enclosure so formed is an inner opaque metal plate 25. This plate may be secured as at 26 to the face of the instrument frame 21. Plate 25 extends radially beyond the wall of opening I! in plate l5. Near the outer margin of plate l5 there are openings 21. Suitable fastening means 29 secure a socket 3| in an opening in plate 9, the socket carrying a light bulb 33 within the housing. From the light source light is distributed around the wall I and passes through the openings 21 into the Lucite face l9. On the glass are etched markings 35 from which the light is transmitted to the observer.

An odometer of conventional form is represented by numeral 31 and is supported by frame 21. Its figures are lighted-by the. light within the housing coming from source 33. The reflected light is seen by the observer through PATENT OFFICE 2,124,089 ILLUMINATED SPEEDOMETER Henry C. Stuerzl, Flint, Mich., assignor' to Ge eral Motors Corporation, Detroit, Mich., a 912- this stem is secured the central part 43 of a point- 5 1 another painted surface marked 5|.

ment frame. One end of this bar passes through source through said glass to be reflected from Lucite I9, opening I1 and through opening 39 provided for the purpose in the inner plate 25.

The speedometer is provided with a stem 4| extending through an aperture in plate 25. To

er 45. Clamped to the central part of the pointer is an opaque disc 41. The pointer is formed from any suitable transparent material such as Lucite. Upon the front face of the central part 43 is a coating of white paint marked .49.- On the rear face of the pointer adjacent its tip is It is intended that light from the source be transmitted to the central region 43, then transmitted by internal reflection to the region 5| from which it is light from the light source there is shown a refiector 53, the reflector being provided with an opening 55. A clamp 51 secures a bar 59 of transparent material such as Lucite to the instru- 20 opening 55 and extends to a point adjacent the light source.. At its other end the Lucite bar is curved as at 6| so that its extremity extends axially toward the painted center 43 of the pointer.

By the construction described above the markings 35 on the glass are the only parts of the glass which are visibleat night. Through the glass ll and inwardly of the markings, the observer sees the light reflected from the surface 51 of the pointer. The position'of part 5| relative to the marking on the glass gives the speedometer readings. The odometer readings are seen through the Lucite IS, the opening H, the transparent part of the pointer and the opening 39. By this construction the light from the source is very advantageously used particularly because the Lucite bar takes the light from immediately adjacent the source and by internal reflection directs it axially to the painted surface of the pointer.

I claim:

1. An indicating instrument having a housing, a source of light therein, a transparent disc coveri'ng'said housing, said transparent disc having markings, means for transmitting light from said said markings, opaque plates at the rear of said transparent disc, a rotatable member between 0 said opaque plates, said rotatable member having a first painted region, and a second painted region spaced from the first region whereby light received by the first region is transmitted by internal reflection to the second region and refiected therefrom to an observer, and a bar of transparent material withinsaid housing associatedv with said source and adapted to transmit light by internal reflection from said source to said first mentioned region.

2. The invention defined by claim 1, the first one 01' said painted regions being located substantially at the axis of rotation of said rotatable member.

' HENRY-C. S'I'UERZL. 

